


Tight Chested

by ArmaniWorks



Series: Thiccverse - Thicc Falls [4]
Category: Gravity Falls
Genre: Gen, Thicc Falls
Language: English
Status: Completed
Published: 2019-06-13
Updated: 2019-06-13
Packaged: 2020-05-07 06:22:12
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,870
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19203679
Author URL: https://archiveofourown.org/users/ArmaniWorks/pseuds/ArmaniWorks
Summary: Mabel reflects on how much has changed between her and Dipper, reveling in past and present memories.





	Tight Chested

It was safe to say that there was very little off-limits to either of the Pines Twins’, sharing everything from a young age, from the bathtub to the clothes on their backs. No surprise, things were to change once they began to grow in age and personality, their bodies progressing to a degree that neither one could deny that there were some differences that could not be denied. However, even that was not enough to stop the both of them from understanding each others’ needs, barriers blurring as they give each other whatever they could to in order to bring a smile to their faces. With this bond, the Twins faced difficult challenges and prevailed through situations where a single one of them would have fallen, coming to each other’s aid through the darkness and allowing them both to shine.

While not one of those critical moments in their lives, this is one of those instances where one Twin had placed restrictions on the other…

 

* * *

 

 

“Dipper! Dipper, where’s your big butt hiding at?” Mabel Pines bellowed, peeking around the corners of the Mystery Shack as if on the hunt for some mysterious creature, eyes keeping upwards out of habit from her brother’s massive structure making him far taller. A memory struck her as she made for the stairs, chuckling to herself as she remembered the first time they arrived at the Shack after his growth spurt, haphazardly smacking into the tops of door entrances. Her tongue peeked out the front of her mouth as she lamented on one of the few times she had tricked her male counterpart, daring him to jump off the stairs at the same time in order to see just whom could reach the bottom the fastest. Mind, it wasn’t something that he was eager to accept, yet it had taken the long-haired brunette only a minor amount of goading to make him see her way.

The second that their feet left the stairs, both Pines immediately regretted their decisions.

Her chest had already reached the point where her bras were little more than cheap decorations, mammaries wobbling against her homemade sweater and snapping the underwire of her cheap dime-store undergarment like it was made of string. Mabel would never forget the feeling, the reminder that gravity itself was just as great an enemy as Bill was as her breasts wobbled underneath her clothing. Clutching the underside of her chest, she bit through the pain, looking back at the madness she had unleashed. Dipper himself had become caught up in his sister’s energetic personality; a normal habit that he would, to this day, never be able to cure. Strong legs had propelled the teenager ahead and for a few split seconds, he believed that he would come out on-top of his sister. Unfortunately, he shared an unfortunate habit with his elder-slash-idol, Grunkle Ford Pines: Always remember to carry the four.

Momentum carried the boy clear ahead and while he reached the bottom alongside his sister, his added weight did nothing for the worn floorboards of the age-old shack. The creaking floorboard that had become a staple of their entering the home had become the poor boy’s undoing, snapping under the immediate force and weight of the larger Pines and causing him to come careening through the floor and into one of the many lower-levels of the Mystery Shack. Mabel couldn’t help but bellow out in laughter as she clutched her sides, half out of pain and the other out of sheer indulgence, her brother’s cry of surprise and the residual crashing of his burly body plowing through termite-infested flooring making it all worthwhile.

 

 

* * *

“C’mon Dip-Do~p!” Mabel tiptoed through the hallway, whispering as faintly as she could while under the effects of her signature beverage. “Stop hiding from your favorite sister and come ou~t.” There was a slight pause as she waited for the inevitable response of ‘You’re my only sister, you nut!’, frowning at the silence that followed. Her eyes began to perk as the sound of running water caught her attention, padding through the Shack’s upper level in her Waddles-branded socks until she reached the bathroom door. Immediately throwing herself against the wood, she placed her ear against the flat surface to hear the sounds of her twin brother humming softly as he scrubbed at his giant frame. “La~me!” The woman pouted, her back coming against the door and sliding downwards, head slumping down and coming to rest in the comfort of her pillowy cushions. “He didn’t use to shower this much… at least, not before Ciffy came along.”

It was true that Pacifica had changed a lot of things for the Pines, especially for Dipper. The boy had become wrapped around the blonde’s finger like a cheap plastic tie, yet Mabel couldn’t deny that the girl had been just what her brother needed in his life. The millionairess had immediately pushed her new boyfriend into taking a shower every day, a habit that had proven difficult to break until she started to deny him touching privileges, which had fixed things right quick. However, she couldn’t bring herself to tell them that she had actually grown accustomed to his scent, sometimes latching herself to his backside in the guise of attempting to take down her bear of a brother, only to take in his scent and frown at the springtime-fresh smell that emanated.

Stomping back to the shared bedroom, the top-heavy twin quickly took to her disheveled bed, spinning around on her heel to face her brother’s side and puffing her cheeks out as her padded bottom came into contact with the worn mattress. Looking at the larger, metallic bedframe only served to remind her of how they had been changing, another memory coming to the surface and taking hold. Their old beds had certainly been less-than-adequate for the growing Pines and while they had all realized it, money had been tight and Dipper was adamant about not borrowing at all from his girlfriend.  **‘I’ve still got enough pride to take care of this, myself.’** were his exact words, Mabel recalled, chuckling to herself as she remembered that it was she who had wheeled and dealed when it came to replacing both mattress and frame. A testament to her Grunkle Stanley’s expert haggling, especially when it came to the fact that she had to glitter-bomb her way out when the dealer realized the fact that he’d been ‘Looney-Tunes’d’ into cutting the price down to 75% of the original.

**‘Words and wit will get you anywhere in life, but sometimes a smoke bomb is your best way out!’** the elder had spoken in one of his many teachings of the illicit.

The beds themselves were fair enough in getting them through a small portion of their time in the Falls… at least, until Dipper had given into impulse and tried to bed his millionaire girlfriend. Mabel could still remember the feel of her expression as she tried to watch television in hopes of drowning out the sounds of her brother and archrival seeping through the poorly insulated floors. Even turning up the volume had done little good, each click of the remote only serving as some kind of psychic signal for her brother to increase his efforts, Pacifica’s cries becoming louder and sharper with the tempo. Mabel finally threw her head into the cushion of their couch, covering her head with an old throw pillow as she tried to drown out the sounds of lovemaking, rhythmic thumps pounding into her head until finally the growl bubbling within her gullet finally grew to bursting.

Rising to her feet, the twin quickly scanned around the hazard zone of a living room until something caught her eye, Mabel snatching up a broom lying in the corner and using it to thrust against the ceiling as she’d seen in so many old movies and cartoons. The action was far from lost on her, face too hot and cheeks too puffed out from the mental image of her brother thrusting into his girlfriend refused to leave her mind. “Dipper Pines, would you just finish and be done with it!?” The second the words left her mouth, she immediately regretted them, cheeks ripening into prime tomatoes as she sputtered in disbelief at her own choice of words. There was a slight pause, voices and motions drawing to a standstill as the Shack became silent.

A loud crack jarred Mabel from the pregnant pause, stepping back out of surprise as the sound of something heavy crashing into the floor came to accompany it, followed by familiar voices crying out in panic. Mabel immediately rushed to the staircase, quickly skipping multiple steps in the process as she ran to their bedroom door and tossed the dirty sock aside without care and threw the door open. While the blush had faded in the panic for her friend’s care, it returned as a gentle glaze as she looked at both her rival and brother completely naked atop the broken structure that was once his bed.

The mattress was completely bent down the middle, yet both blonde and brunette still remained connected in coitus, sheets draped around their bodies. The large-chested twin couldn’t help but notice how both their bodies had gained a light sheen of sweat from their intense session, Pacifica’s disheveled hair sticking to both their hers and her lover’s chest. Her eyes became drawn to the million-dollar rump resting upon Dipper’s midsection, light bite-marks decorating her bare bottom alongside one large red handprint. Both their faces were cherry-red, though Mabel couldn’t tell if it was from embarrassment or exhaustion.

There was a moment of silence as the couple stared at the door, neither party wanting to move for the sake of having to explain what happened around them. Time seemed to stop until the motion of Pacifica’s large bottom caught both siblings’ attention, million-dollar money-maker slowly pressing downwards as she reflexively moved along Dipper’s firm asset. The larger sibling trembled from the feeling of his girlfriend taking him in and both their eyes bulged from the subconsciously intimate action. Mabel bit her tongue lightly as her cheeks began to bulge, blowing a raspberry as the laughter finally became too much for her to hold in, bending over in a fit of merriment. Pacifica’s expression soured, embarrassment finally giving her reason to cover her bare chest with an arm, her other hand coming to rest on Dipper’s barrel of a chest.

“Don’t you  **dare** laugh at me, Mabel Pines!” The blonde sputtered. “Th-this isn’t funny in the LEAST!” Despite her words, the boy beneath the tight bottom couldn’t help but join his sister, finding nothing but amusement in the embarrassing situation. Pacifica would have none of it, pounding her hand atop his chest as he leaned forward to hug her tight.

The next day, Pacifica had immediately sent for another set of frames and mattresses, directing the moving men as if it were her own place. “There’s no way I’m going to go through  **that** again unless it’s on a bed that can actually support that monster of a body.” She thumped the flat of her palm against the front of his shoulder, not bothering to look him in the eyes. Her whole body language screamed embarrassment, yet Dipper couldn’t help but make a jab at the blonde bombshell, both literally and figuratively as he carefully pat her jeans-covered bottom.

“If I recall correctly, didn’t it break because  **someone** forgot herself and pounded into me too hard?”

Mabel remembered the air turning heavy and hot with fury, her fight-or-flight instincts immediately flaring up as Pacifica turned towards Dipper with the kind of look the blonde normally would reserve for her. Neither she nor the moving men stuck around to find out what happened, but Dipper himself swore that everything ended perfectly fine, despite the fact that had multiple bruises along his whole body.

 

* * *

 

 

The brunette sat atop her brother’s bed completely topless, save for a pair of pink panties with the drawing of a  pig’s face on the front and its curly tail on her backside. She couldn’t help but let her mind drift, the fact that her brother had been crafting so many new and interesting memories with someone other than herself. Mabel looked to her side and clutched at the closest thing available: her brother’s shirt, wrapping it around her body and pulling it tight around her body. It took some effort, managing to contain her massive mammaries within the confines of the flannel under the impression that she kept her arms wrapped around her breasts. She didn’t want to think about it, but deep down Mabel knew that eventually her brother would have to move on with his life, either looking into some kind of future with the millionairess or pushing himself towards one of his many interests. The brunette used her arms to push her chest upwards, burying her face within the warm confines and taking in Dipper’s residual scent of pine needles and his own natural odor and for a moment, found a small amount of comfort in being surrounded by his essence.

“Mabel!” Her face snapped back up to look at the giant dripping-wet male standing in the doorway, Dipper clutching a towel tightly around his torso. “PLEASE don’t tell me that’s my favorite shirt you’re wearing?”

“Umm…” Her body tensed slightly, the small amount proving to be the shirt’s limit as the garment began to tremble almost comically, the twin’s face akin to a child caught red-handed. “May~be?” The second the word left her lips, the buttons took flight from her front, breasts blossoming forth into their full splendor as the shirt stretched to give the woman ample room to breathe properly.

“I can’t believe this, that’s my favorite shirt!” The twin groaned, free hand coming to rest upon his forehead. “How many times have I told you not to wear my shirts like that, Mabel? You’re stretching them!”

“Then maybe you shouldn’t wear such comfy, cozy shirts?” Mabel stuck her tongue out, shaking her body to accentuate the point. It certainly  **wasn’t** a lie that his clothing was quite comfortable, as she would sometimes steal his flannel more often than she cared to admit for casual comforts more than she would care to admit.

Shaking his head slightly in irritation, Dipper advanced forward, hand outstretched.

“Look, just give it here, okay? Maybe it’s not that bad…”

“Nope!” She wrapped her arms around her stomach, pressing the cloth tight against her body, tongue still poking out between pink lips in a teasing expression. “It’s mine now, Dip-dop!”

“Mabel, that’s not funny.” Dipper growled. “C’mon, give it back.”

 

She couldn’t help but smile at the rise she got out of her larger sibling, knowing exactly how to push his buttons. “Nope, gotta catch me first!” She teased, quickly planning her escape from the small bedroom. Mabel didn’t know what the future held, but she’d make sure to hold on to the bond with her twin as best she could. That, however, didn’t mean that she couldn’t torment him as only she could do best.

 

* * *

 

 

Pacifica stood in the living room, still completely frozen in-place as she watched the madness around her unfold. The millionairess had come over in expectation of a quiet date night in front of the couch with some popcorn and eventual ‘fun’ to be had once whatever movie Dipper would choose reached a lull… which, considering his taste in movies, would likely happen the second someone started talking about aliens or some kind of science. Regardless, she was  **not** expecting to see him chasing Mabel around wearing nothing but a sopping wet towel. What made things more befuddling was the fact that the large-breasted brunette was wearing nothing but what Pacifica knew to be Dipper’s favorite flannel shirt, mammaries bouncing lightly as the energetic twin pranced around the building with ease. It was almost comical to see her dancing circles around the more muscular Pines, easily keeping out of reach as Dipper slowly became more fervent and animated in his chase.

“Damnit Mabel, give me that shirt back!” He leaned over a chair, stretching his arm out as Mabel leaned forward to flaunt the desired garment and flash a small amount of chest in the process.

“No way Dipper, it’s mine now!”

“Mabel Pines, you take off my shirt, right now!!”

The woman laughed as she literally danced around the cluttered living room, winking at the confused blonde as she used the bottom-heavy woman as a shield. “No way, you’ve got to catch me first!”

“Don’t you dare tempt me, Mabes!”

All Pacifica could do was lower her head into her hand, lips curling into a smile as a small fit of laughter began to bubble from within her ample chest, the Twins spiraling around her their own little world as both siblings yelled and screamed at each other. “This is my family.” She muttered to herself, shaking her head. “These are the people I’ve come to love…” Her eye drifted open slightly to catch the sight of Dipper’s towel falling to the floor and continued to shake her head in dismay.

 

**Author's Note:**

> You know, it's weird. I'm proud of this piece and disgusted by it at the same time. It's definitely going on the list for a redux, but for now, it serves its purpose greatly. A lot of the lore that I set up in here still holds water, but my writing has improved so much between the original posting and now that I know I could do better with it.
> 
> BTW, I have a Twitter, if you want to support me.


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